Hydraulic power transmission unit for driving an intermittently secured member



Nov. 27, 1962 R. F. HERETH ETAL 3,

HYDRAULIC POWER TRANSMISSION UNIT FOR DRIVING AN INTERMITTENTLY SECURED MEMBER Filed March 2, 1962 2 Sheets-Sheet 2 INVENTOR.

A #59576 YO/V/ZJ? 5077276 7510 Patented Nov. 27, 1962 3,065,674 HYDRAULHC PflWER TRANdMiSSifiN llNlT FQR DRIVING AN ENTERMITTENTLY SECURED MEMBER Ralph F. Hereth and Gmer R. Butteriieid, Port fire-hard, Wash, assignors to the United States oi America as represented by the Secretary oi the Navy Filed Mar. 2, 1962, Ser. No. 177,7ii5 4 Claims. (Cl. 8-1.7) (Granted under Title 35, US. (Code (1952), see. 2%

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

The present invention relates to hydraulic power transmissions and, in particular, to transmissions for applying hydraulic power to an intermittently driven and secured member.

Although the present invention will be found to have a variety of applications, it has proven particularly advantageous for use in a guided missile launcher system of the type generally described in copending patent application Serial No. 177,713, Rammer Head Hoisting Apparatus, filed March 2, 1962, further identifiable as Navy Case 33,097.

This shipboard launcher system is designed to launch supersonic surtace-to-air weapons that employ semi-active guidance systems, the target being illuminated by a shipbased radar transmitter operating through a computer to fix the missiles initial boost course, as well as its acquisition phase in which the computer controls missile wings to correct course deviations. The boost phase set by the computer obviously is a straight-line course so that one requirement of the launcher is that the initial firing position be closely locked onto this course.

To so position the launcher for firing, the system utilizes launcher arms and hydraulic power drives capable of training and elevating the arms into the desired collision course set by the computer. Of course, when the launcher and its missiles reach their computer-directed heading, train and elevation power no longer are needed, the launcher arms stopping and securing at this desired heading.

Consequently, because the train and elevation drives for the launcher arms are used only on an intermittent basis, conventional power drives involve substantial wastes of power. More specifically, conventional train and elevation power drives employ as the most effective transmission unit a combination of a standard electricallydriven A-end pump with a B-end motor and, in use, both the pump and motor are constantly driven even though the motor is not performing any useful work. The resulting power loss is accepted as being inherent in the operation.

Another inefilciency of such conventional launcher systems lies in their need for additional hydraulic drives for a variety of other components, such as the hydraulicallydriven rammer head mechanism of the previously identified copending patent application. As will be appreciated, separate pumps for such other components are unnecessary.

It is therefore one of the present objects to increase the efliciency of missile launcher train and elevation power drives.

In a more general manner, another object is to provide a hydraulic transmission for intermittently driving a securable driven member.

A further object is to reduce to a minimum the number of hydraulic drives needed for hydraulic systems such as the described missile launcher.

A further object is to increase the efficiency of such hydraulic drives by utilizing the power generated during idler intervals.

Still another object is to assure the utilization of the drives precisely at the moment the intermittently-driven member is secured.

Other objects and attendant advantages will become more apparent in the ensuing description.

The preferred embodiment of the invention is illustrated in the accompanying drawings of which FIG. 1 is schematic representation of a combined A and B end pump and motor modified according to the present principles, the valves being shown in the JCLC. convention;

FIG. 2 is a sectional View of a transfer control valve similar to that shown in FIG. 1.

Referring to FIG. 1, certain of the components there illustrated have been used in conventional missile launcher hydraulic drives and, as such, are exemplary of the prior art. These conventional elements include an electric motor 1, an A-end hydraulic pump 2, a Bend hydraulic motor 3, a motor drive shaft 4, and a gear reduction unit 6 coupling drive shaft 4 to the load which is illustrated as a ring gear 7. As seen, the output of gear reduction unit 6 drives a pinion i3 meshed with gear 7.

in the launcher application, all of the components already mentioned, except for ring gear 7, are carried by a turret (not shown), the previously-mentioned launcher arms onto which missiles are loaded for firing also being carried by and movable in train with the turret. Train movement is imparted through the rotational drive of pinion 8, it being understood that ring gear 7 is stationary and that the rotation of the pinion carries the turret and its illustrated drive about the circle of the ring gear in a train movement.

In addition to the train movement, the launcher arms are rotatable about a horizontal axis to provide the elevation movement essential for positioning the arms on a directed collision course with a selected target. However, the drive for the elevation is essentially identical with th illustrated train drive, the only difference being that, instead of a horizontal ring gear 7, the pinion output is l ieshed with an elevation gear (not shown). Since this output to the load is not a significant part of the invention, there should be no need for any further consideration of the elevation or train mechanical connections.

Another consideration which will be readily understood is that the A and B end hydrauhc units permit reversal of drive direction as well as speed variations. These factors, of course, are necessary and they result from the conventional operation of these units. Again, however, these features, as well as other details of the pump and motor combination, are well known in the art and should require no special illustrative analysis.

As indicated, A-end pump 2 is driven by an electric motor 1. In practice, the motor may be a -H.P. squirrel cage induction motor having a constant speed output coupled through a suitable gear reduction unit and flexible coupling to an A-end pump drive shaft 9. The A-end pump may be a standard constant speed, variable displacement piston-type pump having a number of reciprocable pistons mounted at one end in cylinder barrels and having their other ends carried by a tilt plate. in the well known manner, the tilt plate receives the constant speed output of the electric motor, and as the tilt plate rotates, the pistons are reciprocated in their cylinder barrels to pump the fluid output. The tilt plate can be positioned to vary the piston reciprocation and the pump displacement. Also, the tilt plate angle can be reversed to control the direction of the drive. Such pumps sometimes are referred to as swash-plate pumps. Other standard pumps may be employed.

s atters The B-end motor 3 used in the launcher is quite similar to the A-end pump although, in the normal manner, the pistons are reciprocated by the axial flow received from the pump and piston reciprocation is converted into an output rotational drive. This operation, of course, is the reverse of the pumping arrangement in which the piston rota-tion produces an axial hydraulic output flow to the B-end. The pump output fluid quantity controls the B-end speed and in actual practice, the unit operates in response to input train elevation orders to convert the constant speed output of the electric drive motor into a variable speed, variable direction output. As indicated, any transmission assembly capable of this performance is acceptable for purposes of the invention. In fact, the speed and direction control will be seen to have no particular significance as far as the inventive principles are involved.

In prior launcher practice, the conventional transmission assembly already described involves substantial power losses in that A-end pump 2 was coupled to B- end motor 3 by a closed circuit shown in the diagram of FIG. 1 as including a pump discharge line 11 and an intake line 12. The power loss occurred because the pump power was continued even when the train movement was secured. The same, of course, applied to the elevation power drive. In addition, the rotating launcher turret carries many other hydraulic components, such as the previously mentioned rammer drives and numerous control valves, pilot valves, blast door operating mechanisms, locking mechanisms, and pressure heads for these components obviously are needed.

The present invention modifies such standard power drives to permit dual function or operation that employs the otherwise wasted power in an unusally effective manner to provide a power source for the other hydraulic components of the launcher or of any hydraulic system utilizing these present principles.

As shown in FIG. 1, these purposes are accomplished by coupling a transfer control valve 14 into the A- and B-end closed circuit 11 and 12, this closed circuit further being identified as a first hydraulic circuit. Functionally, valve 14 transfers A-end pump power into a second hydraulic circuit 15 that includes a standard check valve 16, an accumulator 17, various other hydraulic components of the launcher turret identified as work 18, tank 19 and hydraulic transmission lines 21, 22, 23, 24 which, respectively, couple valve 14 to the accumulator, the accumulator to the work component 18, work to tank 1?, and the tank back to the transfer Valve.

In actual practice, the A- and B-end units are physically interconnected by a valve plate (not shown) provided with appropriate intake and discharge ports. Valve 14 then is bolted to the valve plate and communicated with the ports to direct the flow into second hydraulic circuit 15. For illustrative purposes, valve 14 is shown coupled to pump discharge line 11 by a transmission line 26, and to intake 12 by line 27. Such a rearrangement is needed for the flow diagram and, of course, it does not affect operation.

Another component used in actual practice but not presently shown is a replenishing pump employed to maintain line pressure smoothness and to replenish the A-end pump when its supply is being used to charge accumulator 17. Although this pump is not essential, provision for it is made in transfer valve 14 which will be described later in some detail. An auxiliary power unit may be used to operate the replenishing pump it tank 1? does not have sufiicient head.

Accumulator 17 is a standard unit the purpose of which is to store hydraulic fluid under pressure to provide power to operate work components 18. In practice, plural nitrogen-charged accumulators are connected in parallel to a common manifold, each accumulator being a flask or bottle having a gallon capacity. Also, the charge accumulated is dependent upon the needs of the system. For

example, in the launcher application, the train power drive is coupled through transfer "alve 14 to a high pressure accumulator system in which four accumulators are used to establish a supplementary source of hydraulic fluid at 1100-1750 p.s.i. for peak demands, i.e. periods when the train A-end is not supplying oil to the system. The system may be precharged with nitrogen by means of a conventional valve arrangement coupling a common nitrogen charging port to the used nitrogen bags. Pressure can be regulated by relief valves and pressure gages.

Similarly, the elevation A-end is used in the launcher to provid a low pressure accumulator system that utilizes two nitrogen-charged 5 gallon accumulators to provide a source of fluid at 400-750 p.s.i.

The manner in which valve 14 is controlled to permit the establishment of high and low accumulator pressure systems is another significant feature. Valve operation is required when the intermittently driven launcher arm or other driven member is secured. To achieve this purpose, a special latch 3% is employed to secure drive shaft 4, the latch being hydraulically actuated and, preferably, controlled by a pilot valve (not shown) which, in turn, may be solenoid-controlled through appropriate relays to assure timely operation.

Latch 30 also includes a pair of switch mechanisms 31 and 32 coupled by electric leads 35 and 34 to solenoids 36 and '37 of a transfer valve pilot 38. Consequently, the latched or unlatched condition of drive shaft 4 is signalled and relayed by switches 31 and 32 to the solenoids which position the spool of valve 38 to port hydraulic pressure to one or the other side of transfer valve 14. As seen, valve 14 has a pair of hydraulic cylinders 39 and 41 coupled by hydraulic transmission lines 42 and 43 to pilot valve 38. The hydraulic control pressure for valve 38 usually will be part of work 18.

In the position in which valves 38 and 14 are shown, it is assumed that the launcher has been driven in train to its computer-directed position and that this fact has been signalled through relays to the latch with the result that the latch has engaged the drive shaft. As the latch engages, its switch 32 closes circuit 34 to energize solenoid 37 and position the spool of valve 38 to port oil to cylinder 39. The net result is that valve 14 is set to transfer A-end pump pressure through line 26 into sec- 0nd hydraulic circuit 15 to charge accumulator 17. Re-

turn flow then proceeds through lines 24 and 27 back to the A-end, the replenishing pump making up any deficit due to the accumulator charge.

The diagrammatic illustration of valves 14 and 33 of FIG. 1 is according to 1.1.0 (Joint Industrial Conference) symbols, these symbols being used rather widely as a standard for industrial equipment. In brief explanation, it may be noted that valve 38 indicates a two-position valve, it being understood the valve is provided with a piston or spool and that the two different positions are depicted one on each side of its central line 46. As shown by the arrows in the blocks on either side of line 46, it is apparent that the diiferent positions of the valve simply reverse the flow through the valve so that, for example, the right hand position (FIG. 1) would port pressure to cylinder 41 of valve 14 and couple cylinder 39 to tank.

On each side of the main block of valve 38 are three blocks marked MAN, DET, SOL. The abbreviations connote manual, detent and solenoid. The meaning is that each valve position can be set by the described solenoids or manually. Also, that the positions are detented. For present purposes, the important factor is the solenoid actuation, the alternative actuations being requirements having to do with assuring valve spool operability and stability under shock, vibration or in the event power is cut off. One valve having the structure and operation shown by the ].I.C. symbols for valve 38 forms a part of a copending patent application of Ralph F. Hereth entitled Mass-Balanced Valve Apparatus, Serial lam-) No. 177,715, filed March 2, 1962 and further identifiable by Navy Case 33,098.

Valve 14 also is shown by 1.1.0 symbols as being a two position valve that is hydraulically actuated, i.e. HYD. However, the symbols show that one of the positions (on the right side of its line 46) permits flow through the valve in the direction of the arrows, while the other position simply blocks flow and thus permits the full A-end pressure fio w to be applied to the B-end motor.

Valve 14 also appears in greater detail in FIG. 2, althrough the FIG. 2 arrangement involves some modification and refinement which does not affect present operation. As shown, the valve includes a spool or plunger 51 mounted in a block 52. through which control pressure is admitted. The block also includes a port 53 coupled to A-end pump pressure, a port 54 to accumulator circuit 15, a port s as a return to the A-end, a port 57 from the previously-mentioned but not illustrated replenishing pump, and a port 58 to tank via the power transfer valve.

The valve is shown in the normal or spring off-set position when the launcher is being trained and the A-end is pumping pressure to the B-end motor. As seen, one of the plunger lands blocks port 53 (A-end pressure) from port 56 (accumular circuit) and connects the replenishing pump pressure (port 57) to tank.

The transfer valve is shifted against spring load by operation of the pilot valve 38, this being accomplished, as already explained, when the launcher is latched in train and the A-end pump output no longer is required to drive the B-end motor. In the shifted position, the valve connects port 53 (A-end) to the accumulator circuit through port 54. It also connects the replenishing pump to the A-end pump for accumulator make-up.

Another feature of the invention is the use of latch 30, although the structure and operating rinciple of this valve is the subject matter of another copending patent application, Serial No. 177,714, filed March 2, 1962, by Ralph F. Hereth and George M. Sherman, entitled Rotary Drive Multiple Position Latch and further identifiable by Navy Case 33,099.

For present purposes, it will be suflicient to recognize that this latch operates on a toggle principle to clamp a pair of oppositely disposed clamping jaws 61 about a sprocket wheel 62 that is flexibly coupled to output drive shaft 4. The jaws of the latch are swung open and shut by the toggle arrangement and switches 31 and 32 are placed in the path of the swing to be actuated. The toggle, in turn, is operated by a hydraulic cylinder and piston 63 actuated by a suitable pilot valve (not shown) which is solenoid-controlled.

It is believed that the operation of these various components is completely understandable in the foregoing description. The advantages lie in utilizing the otherwise idled power of the A-end for the purpose of charging accumulators to perform work which, otherwise, would require separate power drives. In particular the use of the toggle latch to engage the B-end output and simultaneously, to signal the secured condition of the train or elevation motors to the pilot valve is a simple, precise and reliable manner of assuring a transfer of A-end power from one circuit to another. In the missile application, it is especially advantageous because of the high and low pressure systems achieved by the train and elevation power drives.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. For use in a hydraulic system having an intermittently driven and secured member and other functional components adapted to be hydraulically actuated during both said driven and secured conditions of said driven member; a hydraulic power transmission unit for both said driven member and said other hydraulic components, said unit comprising a hydraulic pump, a pump motor, a hydraulic motor having a rotatably driven output drive shaft adapted to driveably engage said driven member, means for securing the rotation of said output drive shaft for producing said intermittency, switch means responsive to said securing means for signalling the secured condition of said drive shaft, a pilot valve responsive to said switch means, a first hydraulic transmission circuit communicating said pump and hydraulic motor for transmission of hydraulic power therebetween, a second hydraulic circuit including hydraulic pressure accumulator means, and hydraulic transmission lines adapted to communicate said accumulator means with said other hydraulic components, and a transfer control valve common to both circuits, said control valve being operatively coupled to said pilot valve for alternating transmission of hydraulic pump pressure between said first circuit motor and said second circuit accumulator means as said output drive shaft is secured and released whereby said pump power is continuously applied either to drive said hydraulic motor or to hydraulically charge said accumulator means.

2. For use in a hydraulically-actuated missile launcher system having an intermittently driven and secured launcher arm and other functional components adapted to be hydraulically actuated during both said driven and secured conditions of the launcher arm; a hydraulic power transmission unit for both said launcher arm and said other components, said unit comprising a hydraulic pump, a pump motor, a hydraulic motor having a rotatably riven output drive shaft, gear reduction means coupled to said output drive shaft and adapted to driveably engage said launcher arm, a latch for engaging the input of said gear reduction unit for securing the rotation of said drive shaft, switch means operated by said latch for signalling the secured condition of said drive shaft, a pilot valve responsive to said switch, a first hydraulic transmission circuit communicating said pump and hydraulic motor for transmission of hydraulic power therebetween, a second hydraulic circuit including hydraulic pressure accumulator means and hydraulic transmission lines adapted to communicate said accumulator means with said other hydraulic components, and a transfer control valve common to both circuits, said control valve being operatively coupled to said pilot valve for alternating the transmission of hydraulic pump pressure between said first circuit motor and said second circuit accumulator means as said latch secures and releases said output drive shaft, whereby said pump power is continuously applied either to drive said hydraulic motor or to hydraulically charge said accumulator means.

3. The transmission unit of claim 2 wherein said transfer valve is a hydraulically-actuated spool valve, and said pilot valve is a solenoidoperated two-position hydraulic transmission means transmissively coupling the hydraulically-charged accumulator means to said transfer control valve.

4. The transmission unit of claim 3 wherein said pilot valve includes a pair of solenoids, and a circuit electrically coupling each of said solenoids to said latch switch means, said switch means being arranged to alternate the energization of the solenoids as said latch successively is engaged and released.

No references cited. 

